Type-writing machine.



W. F. HELMOND. TYPE WRITING MAGHINBI APPLICATION FILED M11214, 190s.

Patented Nov. 17, 1908.

UNITED STATES PATENT OFFIOE.

WILLIAM HELMOND, OF HARTFORD, CONNECTICUT, ASSIGNOR TO UNDERWOOD TYPE- WRITER COMEANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

TYPE-WRITING MACHINE.

Specification of Letters Patent.

Patented Nov. 17, 1908.

, Application filed. Kay 14, 1908. Serial No. 432,806.

To all whom may concern:

specification.

This invention relates to springs employed to press the usual pressure rolls against the revoluble platens of writing machines. V

The invention is illustrated inconnection with the systein of forward and' rear pres sure rolls heretofore employed in the wellknown Underwood front strike writing'machines, in which shafts carry the pressure rolls, and arms carry the shafts, the arms being all hinged upon a rod which upon the platen frame.

One of theprmcipal objects of the invention 1 is to improve the construction, mounting and operation of the springs which press the arms or shafts towards the platen, and to make it feasible to secure any desired pressure at any point of the pressure roll system. -Other objects andadvantages will hereinafter appear.

In the accompanying drawings, Figure 1 is a bottom view of a platen frame of an Underwood front strike writing machine provided with my improvements. Fig. 2 is an end elevation of the pressure roll system, showing the parts in normal positions. Fig. 3 is a similar View, showing the rolls released. Fig. i'is an elevation (showing the parts inverted) of one end of av pressure-roll mechanism, showing particularly the manner of securing and adjusting one of the springs. Fig. 5 is a perspective view to illustrale a pair of springs, and other features of ,the pressure-roll mechanism.

wardand rear pressure rolls 10, 11.

is rigid The platen 1 is usually mounted by means of anaxle 2 in theends 3, 4 (if a platen frame. Said ends are rigidly connected by a rod 5; and from this red extend forwardly "Eaud re'arwardly hinged arms 6, 7, said arms carrying releasably at their extreme ends ,shafts 8, 9, upon which are mounted forframe; and upon each of these blocks is secured a pair of springs 13, 14, by neans of screws 15. The springs extend side by side along the rod 5 and at their ends are formed with fingers 16, 17, which extend along the arms 6, 7 to the ends thereof, and there bear up against said arms to pressthe rolls 10, 11 against the platen.

A. screw 18 passes down through each of 12, to draw said spring down toward the block; each spring being bowed or arched away from the block, as at 19, to give clearance for its adjustment by means of the screws 18. By means of said screws 18, any desired pressure may beput upon either end of either roll shaft 8 or 9, and even running of the rolls and accurate feeding of the paper is thereby secured.

Each of the screws 18 is preferably formed with a square head asshown, and upon its yielding forks .20, forming a detent, to hold the screw 18 against turning. The detent is in the form of a loop, the head of which is rigidly held between the head of the screw 15 and the bottom of the spring 13 or 14. The forks 20 are sufficiently yielding to permit the screw 18 to be turned, but sufii ciently strong to prevent it from trrning accidentally, so that the tension of the spring 13 or. 1 1 is preserved.

mounted in this manner, extending side by side along the rod 5, from the ends of the platenframe between the rolls 10, 11, may have suflicient length to give them the required elasticity and flexibility, and also to .permit the employment of the described tens ion adjusting means. If desired, the springs 13, 14, may be released by turning the screws 18' a predetermined number of 10, 11 from the arms 6, 7, without liability of warping or breaking the springs; and upon restoration of the rolls, the tension screws 18 may be turned up the same number of revolutions, thereby restoring the original with open slots 21 to detachably receive the roll shafts.

vided for the pressure. rolls, as for instance the springs, and is threaded into the block It will be seen that springs formed and revolutions to permit withdrawal of the rolls Any suitable releasing means may be proa key 22, link 23, crank 24 and rock shaft 25,.

opposite sides each screw is engaged by 1 tension on the rolls. The arms are provided the latter having flats 26 engageable by release arms 27 formed upon the shaft-carrying arms Sand 7.

Having thus described my invention, I claim:

1. In a typewriting machine, the com bination with a revoluble platen and a platen frame in which the platen is journaled, of forward and rear pressure rolls to run upon the platen, blocks or supports fixed upon the platen frame, a pair of springs secured upon each of said blocks and extend.- ing along the platen, 'to engage means to press the rolls against the platen, and screws passing through said springs. and threaded into said blocks to adjust the tension of the springs independently.

2. In a typewriting machine, the combination with a revoluble platen and a platen frame in which the platen is journaled, of forward and rear pressure rolls to run upon the platen, shafts to carry said pressure rolls, independently movable arms in which said shafts are hung, a rod fixed upon said platen frame and carrying said arms, blocks or supports fixed upon the platen frame at the ends of said rod, a pair of springs secured upon each of said blocks and extending along the'rod to engage said shaft-carrying arms to press the rolls against the platen, and screws passing through said springs and threaded into said blocks to .adjust the tension of the springs independently of one another.

8. In a typewritin machine, the combination with a revolub e platen and a platen frame in which the platen is journaled, of forward and rear pressure rolls to run upon the platen, shafts to carry said pressure rolls, independently movable arms in which said shafts are hung, blocks or supports fixed upon the platen frame, a pair of springs secured upon each ofvsaid blocks and extending along the rod to engage said shaft-carrying arms to press the rolls against the platen, screws passing through said springs and threaded into said blocks to adjust the tension of the springs independ-- ently, and yielding etents for the screws.

4:. Ina typewritingmaehine, the combination with a revoluble platen and a platen frame in which the. platen is journaled, of forward and rear pressure rolls to run upon the platen, independently movable arms for said rolls, blocks or supports fixed upon the platen frame, a pair of springs secured upon each of said blocks and extending along the rod to engage said shaft-carrying arms to press the rolls against the platen, and screws passing through said springs and threaded into said blocks to adjust the tension of the I springs independently, the springs being arched or bowed away from the blocks to permit tensioning by said screws.

5. In. a typewriting machine, the combination with a revoluble platen and a platen.

frame in which the platen is journaled, of forward and rear pressurerolls to run upon frame and carrying said arms, blocks or supports fixed upon the laten frame at the ends i the platen, shafts tocarry said pressure rolls, I

independently movable arms in which, said shafts are hung, a rod fixed upon said platen of said rod, a pair'o springs secured side by A side upon each of said blocks and extending along the rod, fingers extending laterally from said springs to engage I said shaft carrying arms to press the rolls against the platen, screws passing'through said springs and threaded into sald blocks .to-adjust the tension of the springs independently, the screws having square heads, and yielding detents in, theform of forks engaging the opposite sides ofthe screw heads and each secured at one end by a screw which secures the associated sp'Ein to the block.

W L AM F. HELMOND. Witnesses:

' W. M. BYORKMAN,

MORTON C. TALco'rr. 

